Shield kits for projectile protection

ABSTRACT

A shield kit for projectile protection and associated systems and methods. A portable shield kit is disclosed including a flexible shield configured to be fastened to a bar armor frame which is maintained a predetermined standoff distance from a structure, such as a vehicle. The shield kit can be deployed in the field to cover a portion of the vehicle. The shield is configured to prevent a projectile, such as a shaped charge, from detonating as designed.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application hereby claims priority to United Kingdom Patent Application No. ______, filed on May 17, 2011, which is incorporated herein in its entirety by reference.

TECHNICAL FIELD

The following disclosure relates generally to shield kits for vehicles and structures, and associated systems and methods.

BACKGROUND

Shaped-charge warheads, such as RPGs, are capable of penetrating steel armor and pose a particular problem for tanks and armored personnel carriers (APC) in combat situations. A shaped-charge warhead consists of a cone shaped warhead having a quantity of explosive disposed behind a hollow space. The hollow space is typically lined with a compliant material, such as copper. When detonated, the energy is concentrated to the center of the charge and is sufficient to transform the copper into a thin, effectively liquid, shaped-charge jet having a tip speed of up to 26,000 mph. The extremely high pressures generated cause the target material to yield and flow plastically, with devastating effect. To be most effective the shape and structure of the cone of the shaped-charge must be in tact at detonation. If the shape is somehow altered, the shaped-charge jet will not have formed properly before hitting the surface and the effect will be lessened.

Conventional shields for defending against shaped-charge warheads make use of the fact that the shape of warheads enables the warheads to “jet” or penetrate heavy armor. By providing an outer shield at a short distance from the actual armor of the vehicle or other structure that can deform or crumple the cone of the warhead, it is possible to cause the warhead to fail or dud, with the effect that the full design of the charge is thwarted. In effect, the warhead becomes a conventional grenade, rather than a shaped-charge.

Any outer shield that interrupts the detonation design of the shaped-charge will offer some degree of protection. The shield itself merely needs to deform or crumple a portion of the cone of the shaped charge, reducing the impact of the shaped charge to a simple grenade; it is not meant to act as additional armor. In recent times it has become common to fit so-called “bar armor” to tanks and other military vehicles. Bar armor includes a metal frame which is mounted at a distance of approximately 1.5 feet from the vehicle. The frame includes a plurality of horizontal struts or bars which are spaced apart at a distance selected to prevent penetration by shaped-charge warheads. When the shaped charge strikes the bar armor, the bar armor deforms the charge and interferes with the design of the detonation, reducing the damage from the shaped-charge. One disadvantage of bar armor is that it is relatively heavy and adds a great deal of weight to an already heavy vehicle. In addition, bar armor cannot easily be replaced or repaired in the field.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a vehicle having a plurality of flexible shields replacing damaged portions of a bar armor system according to an embodiment of the present disclosure.

FIG. 2 is a front elevation view of one of the flexible shields of FIG. 1 configured according to an embodiment of the present disclosure.

FIG. 3 is an isometric view of a cable support system for use with the flexible shields of the present disclosure.

FIG. 4 is a front perspective view of an installed flexible shield having a cable-reinforced seam configured according to an embodiment of the present disclosure.

FIG. 5 is an isometric view of a seam between two shields configured according to another embodiment of the present disclosure.

FIG. 6 a is an isometric view of a shield kit configured according to an embodiment of the present disclosure.

FIG. 6 b is an isometric view of the shield kit of FIG. 6 a packaged for in-field deployment and configured according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure relates to various embodiments of flexible shields and shield systems which may be used to protect a target, such as a vehicle, building or other structure, from damage caused by a projectile, such as a rocket propelled grenade (RPG) or other shaped-charge. The shields of the present disclosure can be used as replacement shields for bar armor systems configured to interrupt the design of detonation of warheads, rendering them significantly less powerful than intended. The shields can be small and lightweight for portability and relatively easy in-field installation. Many specific details are set forth in the following description and in FIGS. 1-6 b to provide a thorough understanding of various embodiments of the disclosure. Other details describing well-known structures and systems often associated with bar armor systems, however, are not set forth below to avoid unnecessarily obscuring the description of the various embodiments of the disclosure.

Many of the details and features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details and features without departing from the spirit and scope of the present disclosure. In addition, those of ordinary skill in the art will understand that further embodiments can be practiced without several of the details described below. Furthermore, various embodiments of the disclosure can include structures other than those illustrated in the Figures and are expressly not limited to the structures shown in the Figures. Moreover, the various elements and features illustrated in the Figures may not be drawn to scale.

FIG. 1 is an isometric view of a vehicle 110 having a plurality of flexible shields 140 (identified individually as first shield 140 a and second shield 140 b) replacing damaged portions of a bar armor system 100 according to embodiments of the present disclosure. The flexible shields 140 can be the same as or similar to the textile armor described in U.S. patent application Ser. No. 10/584,605, filed Aug. 9, 2007, published as U.S. Patent Application Publication No. 2009/0217811, claiming priority to GB Patent Application No. GB 0601030.0, filed Jan. 17, 2006, both of which are incorporated herein by reference in their entirety. The bar armor system 100 can include conventional armor bars or slats 124 suspended from a perimeter frame 121 that is attached to the vehicle 110 by standoff arms 122 (shown in FIG. 1). The standoff arms 122 project outward from the vehicle 110 a predetermined standoff distance, such as about one foot or more. The standoff distance can vary depending on the nature of the expected projectile attack and on the dimensions of the vehicle 110. The bars 124, the frame 121, and the standoff arms 122 are collectively referred to herein as armor 120. The armor 120 can be divided into discrete panels 123, each panel being defined by a section of the frame 121 and covered by the bars 124. Virtually any suitable panel dimension and bar shape and size can be used. In some embodiments, one of the panels 123 covers the entire rear, side, or front of the vehicle 110. In other embodiments, the individual panels 123 cover a smaller area of the vehicle 110, and in some cases two or more of the panels 123 together cover the entire rear, side, or front of the vehicle 110.

The armor 120 is configured to substantially cover the vehicle 110 from anticipated angles of attack. In some embodiments, the angle of attack cannot be anticipated so the armor 120 can cover the entire vehicle 110. In other embodiments, such as shown in FIG. 1, a lower perimeter of the vehicle 110 is covered by the armor 120 in anticipation that an attack will come from the ground and not the air.

When a projectile such as a shaped charge strikes the armor 120, the shaped charge is deformed by the armor 120, thus preventing the shaped charge from “jetting.” The projectile's destructive power is therefore reduced to generally equivalent to a hand grenade, which can be withstood by the conventional armor of the vehicle 110. However, the armor 120 may be damaged or otherwise rendered inoperable by the blast. Other circumstances can also damage the armor 120, such as contact with rough terrain. Carrying replacement bars or slats for such a contingency is generally impractical. The shields 140 of the present disclosure, however, can be packaged in a kit, conveniently carried on board the vehicle 110, and deployed in the field to cover an exposed portion of the vehicle 110 when a portion of the armor 120 is damaged. The shields 140 can be flexible shields and can therefore cover panels 123 of varying sizes. For example, in the illustrated embodiment the first shield 140 a can protect a portion of the front of the vehicle 110, and the second shield 140 b can protect a side of the vehicle 110. The size and attachment points of the shields 140 a, 140 b when installed may vary according to the size of the damaged area of the armor 120. In some embodiments, the first shield 140 a and second shield 140 b are similar in size before deployment and are packaged similarly.

FIG. 2 is a front elevation view of one of the shields 140 of FIG. 1 according to an embodiment of the present disclosure. In some embodiments, the shield 140 is made from a textile material such as a net having interwoven strands 141 forming square, diamond, or hexagonal holes between the strands 141. The holes can range from about 0.5 inch to 2.5 inches, or about one inch across. The size of the holes in the shield 140 can be selected to defeat a particular type of shaped charge. For example, the holes in the shield 140 can be made slightly larger than a nose of an expected shaped charge projectile, but smaller than the body of the shaped projectile. The strands 141 can be made of various suitable materials, including flexible, lightweight materials such as polyethylene (e.g., high molecular weight polyethylene). In some embodiments, the strands 141 do not stretch appreciably and therefore interrupt the designed detonation of the projectile.

The strands 141 can be aligned in a first direction, wherein each strand 141 is woven with adjacent strands 141 alternating left and right along the length of the strand 141, with a knotless intersection between strands 141, similar to chicken wire or a chain-link fence. In general textile terminology, these strands 141 are known as warp strands. In general, warp strands of a textile are woven in a first direction, and the textile can optionally include weft (or fill) strands interwoven with the warp strands in a second direction transverse to the first direction. In some embodiments, the shield 140 is a textile having warp strands 141 and does not include weft strands. In other embodiments, the shield 140 includes both warp strands 141 and weft strands (not shown).

In embodiments in which the shield 140 is a net having holes, any suitable hole can be used as an attachment point for fastening the shield 140 to the frame 121. Fasteners 142 such as cable ties (e.g., zip ties) or other suitable strap fasteners can extend through a hole in the shield 140 and around a portion of the frame 121 to hold the shield 140 to the frame 121. The size of the deployed shield 140 can therefore be adjusted to fit any size of breach in the armor 120 with any suitable level of tension by selectively installing fasteners 142 in available holes and securing the shield 140 to the frame 121. In other embodiments in which the shield 140 includes tightly-woven warp strands 141 and weft strands (not shown) without holes, the shield 140 can include loops or eyelets or other suitable attachment points (not shown) at any suitable position, including around a periphery of the shield 140, that can engage the fasteners 142 to attach the shield 140 to the frame 121.

The shield 140 can be pulled taut across the frame 121 and fastened with an appropriate amount of slack so that the shield 140 deflects a small amount, but less than the standoff distance, when a projectile strikes the shield 140. An operator can perform a convenient test for the proper slack by pressing on the shield 140 with his hand. The shield 140 can be sufficiently taut that the shield 140 deflects slightly, but the operator's hand does not reach more than about half the standoff distance between the shield 140 and a hull or sidewall of the vehicle 110. This test can be performed in the field without using tools or any other specialized equipment.

FIG. 3 is an isometric view of a first cable 144, second cable 145, and a cable joiner 146 for use with the shield 140 configured according to embodiments of the present disclosure. The cables 144, 145 can be made of steel, polyethylene, cable, and/or other suitable materials. The cable joiner 146 can include two through-holes or channels configured to receive the first and second cables 144, 145 extending therethrough. The channels can be mirrored on opposite sides of the cable joiner 146 to receive the first and second cables 144, 145. The cable joiner 146 can have spring-loaded rollers or wedges in the channels configured to permit the cables 144, 145 to move through the cable joiner 146 in one direction only and grip the cables 144, 145 when pulled in the opposite direction. In some embodiments, the cable joiner 146 is a conventional gripple as provided by, e.g., Gripple Ltd. of Sheffield, England.

The cables 144, 145 can be fastened to opposing portions of the frame 121 shown in FIG. 2. In some embodiments, a first portion 144 a of the first cable 144 extends between the frame 121 and the cable joiner 146, and a second portion 144 b of the first cable 144 is trimmed near the cable joiner 146. A first portion 145 a of the second cable 145 can similarly extend between the frame 121 and the cable joiner 146, and a second portion 145 b of the second cable 145 can also be trimmed near the cable joiner 146. The first portions 144 a, 145 a can be tensioned by pulling the second portions 144 b, 145 b away from the cable joiner 146 as shown by arrows A. In some embodiments, the cables 144, 145 can be interwoven with the shield 140. In other embodiments, the shield 140 can be attached to the cables 144, 145 with the fasteners 142 via holes, loops, eyelets, or another suitable attachment point on the shield 140 as described above.

In some embodiments, the second portions 144 b, 145 b of the first and second cables 144, 145 can be secured to other portions of the frame 121 to pull the cables 144, 145 away from the shield 140 to further tension the shield 140. The shield 140 can therefore be enlarged and shaped. For example, an edge 143 of the shield 140 can be non-linear, following the shape of the first portions 144 a, 145 a of the cables 144, 145. This method can also be used to achieve proper tension in the shield 140. The cables 144, 145 therefore form a replacement frame that holds the shield 140 in place. Accordingly, even when a portion of the frame 121 is damaged or missing, the cables 144, 145 support the shield 140 with a desired tension in the shield 140.

FIG. 4 is a front perspective view of a shield installation with a cable-reinforced seam 200 configured according to an embodiment of the present disclosure. The first and second shields 140 a, 140 b can be fastened to the frame 121 with a plurality of the fasteners 142 installed along three sides of each shield 140 a, 140 b with the remaining side of the shields 140 a, 140 b positioned adjacent to one another in the middle of the frame 121. A first cable 144 can be fastened to the frame 121 at a first cable attachment point 150, and a second cable 145 can be fastened to a second cable attachment point 151 opposite the first cable attachment point 150. In some embodiments, the first and second cables 144, 145 can be wrapped around any available portion of the frame 121 and tied off. In other embodiments, the first and second cable attachment points 150, 151 can be specifically designed to engage and anchor the respective end portions of the cables 144, 145. For example, in some embodiments the cable attachment points 150, 151 can be knobs, hooks, or cleats.

The cables 144, 145 can be woven through holes along the adjacent edges of the shields 140 a, 140 b and joined together with the cable joiner 146 and tensioned as described above. The second portions 144 b, 145 b of the first and second cables 144, 145 can either be trimmed or can be attached to some portion of the frame 121 or the shields 140 a, 140 b.

The first and second shields 140 a, 140 b together form a composite shield 140 c covering the entire panel 123. The cables 144, 145 provide additional rigidity and tension to the composite shield 140 c. In some embodiments, the seam 200 can be used when a portion of the frame 121 is missing. For example, when a portion of the frame 121 between adjacent panels 123 (see FIG. 1) may be missing or damaged. Accordingly, the composite shield 140 c and cable-reinforced seam 200 can be used to cover the vehicle 110 when portions of the frame 121 are unavailable.

FIG. 5 is an isometric view of a shield seam 300 configured according to another embodiment of the present disclosure. In this embodiment, the fasteners 142 can directly attach the first shield 140 a to the second shield 140 b, without using a cable or cable joiner. More specifically, the operator can pull the shields 140 a, 140 b together with the desired tension and place the fasteners 142 at any appropriate hole of the shields 140 a, 140 b to maintain the desired tension.

FIG. 6 a is an isometric view of a kit 160 according to embodiments of the present disclosure. The kit 160 includes a shield 140 that is wrapped or rolled into a compact package, fasteners 142, a cable 144, and cable joiners 146. The kit 160 can also include a desiccant material 145, any suitable printed instructions 147, and a marker 148 for indicating when the shield 140 was installed or other information. In some embodiments, the kit 160 weighs approximately 3.5 pounds and is therefore easily portable. In other embodiments including a larger shield 140, the kit can be approximately 7 pounds. FIG. 6 b is an isometric view of the kit 160 of FIG. 6 a as packaged conveniently for deployment in the field.

From the foregoing, it will be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the various embodiments of the disclosure. For example, the shields can be made of various suitable materials and can have various dimensions. Moreover, specific elements of any of the foregoing embodiments can be combined or substituted for elements in other embodiments. Certain aspects of the disclosure are accordingly not limited to automobile or aircraft systems. Furthermore, while advantages associated with certain embodiments of the disclosure have been described in the context of these embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. Accordingly, the disclosure is not limited, except as by the appended claims. 

1. A shield kit for protection against explosive projectiles, the shield kit comprising: a flexible shield including a plurality of attachment points extending at least partially around a periphery of thereof; and a plurality of fasteners configured to engage the attachment points and engage a frame member mounted to a vehicle to hold the shield to the frame member, wherein the frame is spaced apart from an exterior surface of the vehicle.
 2. The shield kit of claim 1 wherein the shield comprises a net.
 3. The shield kit of claim 1 wherein the frame member is spaced apart from the exterior surface of the vehicle by a standoff distance, and wherein the fasteners are configured to fasten the shield to the frame member with sufficient strength to prevent the shield from deflecting more than the standoff distance.
 4. The shield kit of claim 1 wherein the shield comprises a textile shield.
 5. The shield kit of claim 4 wherein the shield comprises strands connected with a knotless intersection.
 6. The shield kit of claim 4 wherein the textile shield comprises interlocking warp strands and weft strands.
 7. The shield kit of claim 1, further comprising a cable configured to span between opposing portions of the frame and engage the shield to maintain tension in the shield.
 8. The shield kit of claim 1 wherein the shield is a first shield, and wherein the shield kit further comprises a second shield and a cable configured to span between opposing portions of the frame and engage the first shield and the second shield to maintain tension in the first shield and second shield.
 9. The shield kit of claim 1 wherein the fasteners comprise cable ties.
 10. The shield kit of claim 1 wherein the shield and the fasteners are configured to be contained within a portable package.
 11. A shield kit for replacing portions of a bar armor system to protect a vehicle against explosive projectiles, the shield kit comprising: a first flexible shield comprising a plurality of interwoven flexible strands with openings between the strands from about one inch to about four inches; a second flexible shield; means for fastening the first flexible shield and the second flexible shield to a frame, wherein the frame is attached to the structure and spaced apart from the structure by a standoff distance; a first cable configured to attach to a first point on the frame and engage the first flexible shield and the second flexible shield; a second cable configured to attach to a second point of the frame opposite the first point and to engage the first flexible shield and the second flexible shield; and a cable joiner configured to receive the first cable and the second cable and maintain tension in the first cable and second cable.
 12. The shield kit of claim 11 wherein the cable joiner is configured to maintain sufficient tension to cause an incoming explosive projectile to detonate before reaching the structure.
 13. The shield kit of claim 11 wherein the first shield, the second shield, the means for fastening, the first cable, the second cable, and the cable joiner together weigh less than approximately one pound.
 14. The shield kit of claim 11 wherein the cable joiner comprises a gripple.
 15. The shield kit of claim 11 wherein at least one of the first and second shields comprises a textile shield.
 16. A flexible shield for use with a bar armor frame attached to a vehicle, the bar armor frame being positioned apart from the vehicle by a standoff distance, the shield comprising: a plurality of interwoven flexible strands forming a net; and a plurality of loop fasteners configured to engage the net and the bar armor frame and hold the net to the bar armor frame, wherein the net is sufficiently strong to deform an incoming explosive projectile before or during detonation.
 17. The flexible shield of claim 16, further comprising a cable configured to engage opposing portions of the bar armor frame and engage the net to maintain tension in the net.
 18. The flexible shield of claim 17 wherein the cable comprises a first cable, the flexible shield further comprising a second cable and a cable joiner configured to maintain tension between the first cable and the second cable.
 19. The flexible shield of claim 16 wherein the shield, the fasteners and the cable are packaged in a portable kit.
 20. A method for protecting a vehicle against explosive projectiles, the method comprising: carrying a kit containing a flexible shield and a plurality of fasteners; positioning the shield over a damaged portion of a bar armor system on the vehicle; and fastening the shield to a frame of the bar armor system by installing the fasteners through openings in the shield and around portions of the frame and securing the fasteners, wherein the frame positions the flexible shield system away from the vehicle by a standoff distance.
 21. The method of claim 20, further comprising: attaching a first cable to a first portion of the frame; attaching a second cable to a second portion of the frame opposite the first portion of the frame; engaging the shield with at least one of the first and second cables; and tensioning the first cable and the second cable using a cable joiner.
 22. The method of claim 20, further comprising testing the tension in the shield by pressing against the shield and ensuring that the shield does not deflect by more than the standoff distance. 